Gooseberry
When they rang to invite you out
Why didn't you hesitate
'Cos you know they're a couple now
And it'd be like a date
And while you still like their company
Their baby talk makes you gag
And when they get down to pashing on
You're gonna feel like a dag

'Cos they're such a cute couple
Your angle's obtuse
What was once equilateral
Is bent out of use
Now in this tragic triad
You're the minor third
And the giggling sounds absurd
You're the odd one out
One of these things
Just doesn't belong here
Two of these things are having a snog

So you stare every other way
Because you don't want to gawk
You ought to bail out and head for home
Except it's too far to walk
When they suggest a trapezium
Their pity adds to your gloom
Because they both try to set you up
With every dag in the room
Two of these things are going the tongue

Now as you adore every flaw in the wall
And the ceiling's appealing to you
You notice that some of squares
On the other two sides have been
Room gazing too and soon you're aware
That each passionate pair
Has a solitary sad case in tow
Each agonizing whether it's best
To be the odd one out
Or the odd one at home